Table 3.
Characteristics of observational studies comparing early intervention versus conservative management
| Study | Study design | Study population | Age (years) | Follow-up period | Outcomes | Adjustment methods |
| Pai et al11 | Retrospective cohort study | 338 | 71±15 | 7.6 months | All-cause mortality. | Cox proportional hazards model (variables adjusted for age, MR grade 3 or 4, CKD and aspirin use). |
| Kang et al12 | Prospective cohort study | 104 | 63±12 | 49.3 months | Operative mortality and cardiovascular death during follow-up. | Propensity score-matched analysis. |
| Le Tourneau et al13 | Retrospective cohort study | 694 | 71±11 | Average more than 60 months | To assess the value of STS score in predicting short-term and long-term outcome. | Cox proportional hazards model. |
| Taniguchi et al (CURRENT AS registry)7 | Retrospective cohort study (propensity score-matched analysis) |
582 | 71.6±8.7 (AVR group) 73.1±9.3 (watchful waiting group) |
45 months (median) | All-cause mortality and hospitalisation for heart failure. | Propensity score-matched analysis. |
| Masri et al14 | Retrospective cohort study | 533 | 66±13 | 82.8 months | All-cause mortality. | Cox proportional hazards model (variables adjusted for STS score, age-sex-predicted METs and heart rate recovery). |
| Bohbot et al15 | Retrospective cohort study | 281 | 73±10 | 42 months | All-cause mortality and cardiovascular death during follow-up. | Cox proportional hazards model (variables adjusted for age, sex, body surface area, hypertension, coronary artery disease, atrial fibrillation, Charlson Comorbidity Index, AVA, peak aortic jet velocity, EF and LV mass). |
| Campo et al16 | Retrospective cohort study | 265 | 68.1±11.7 (AVR group) 73±12.6 (watchful waiting group) |
60 months | All-cause mortality. | Multivariable Cox regression model (variables adjusted for age, renal failure and ejection fraction). |
| Kim et al17 | Retrospective cohort study | 468 | 64.2±13 | 60.9 months | All-cause mortality, cardiovascular death and MACE. | Time-dependent Cox regression analysis (variables adjusted for age, BMI, anaemia, severe CKD, previous stroke, coronary artery disease, previous malignancy, left atrium diameter, LVMi and tricuspid regurgitation pressure gradient). |
AVR, aortic valve replacement; BMI, body mass index; CKD, chronic kidney disease; CURRENT AS, Contemporary outcomes after Surgery and medical treatment in patients with severe Aortic Stenosis; EF, ejection fraction; LV, left ventricular; LVMi, left ventricular mass indexed; MACE, major adverse cardiac events; METs, metabolic equivalents; MR, mitral regurgitation; STS, Society of Thoracic Surgeons.